S55 HEATER NOISY' / (IN PASSENGER COMPARTMENT) - Alfa - 166 - eLearn

The heater is working properly, but there is excessive noise coming from the duct distributor assembly

1	CHECKING ELECTRIC FAN	All OK	Problems met	Operation
		Results of the tests
	Check the climate control electric fan. In particular, ascertain: there are no foreign bodies inside the fan casing there are no vibrations at the various speeds (causing operation with the fan switched off, but the electrical connection engaged)	Continue to Step 2	Fan dirty	Clean the fan casing and all the ducts
		Continue to Step 2	Electric motor noisy, fan unbalanced	Replace the electric fan Op. 5020A30
2	CHECKING THE AIR DUCTS	All OK	Problems met	Operation
	Check that the air ducts inside the dashboard and the vents are intact and that there are no foreign bodies which could cause noise	Continue to Step 3	Air ducts obstructed or damaged	Restore the operation of the ducts and the vents (see Assembly 5010B)
3	CHECKING DISTRIBUTOR DUCT	All OK	Problems met	Operation
	Check whether there are foreign bodies or damaged parts inside the duct distributor assembly which could cause noise	Continue to Step 4	Air passages obstructed or damaged	Restore the operation of the distributor duct If necessary, replace one of the flaps Op. 5040C24
4	HECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis	Fault persists	Search for the fault starting from another symptom'